In the manufacture of alternating current dynamoelectric machines, such as induction motors, a number of phase windings are emplaced in a stator core of ferromagnetic material. These phase windings, formed of coils of insulated wire conductors and defining circumferentially spaced poles, must have lead wires thereof interconnected and connections made to insulated external power lead wires. As such connections are typically formed by mechanically crimping bared ends of such interconnected lead wires, these connections must be insulated. These insulated connections are subjected to high levels of electrical stress during motor operation and the windings are typically subjected during the manufacturing process to pressure forces to compact and form the end turns thereof. Also, mechanical crimping of the electrical connection may sometimes form small projecting metal burrs or sharp edges that could puncture or rupture the connector insulator or at least reduce its insulation value. It is important, therefore, that the connection insulator be able to undergo various steps in the motor manufacturing process and maintain its insulation value so that the motor will function reliably and effectively and have a long service life. This is particularly true for motors incorporated in a hermetically sealed compressor for an air conditioner, or refrigerator, for example, where motor failure means not simply replacement of the motor but the entire hermetically sealed compressor. In such uses the electrical connector should not contain any components or be fabricated from material which would during usage form compounds or substances which would deleteriously affect the refrigerant, lubricant, the wire insulation or other components of the motor-compressor unit.
A number of different connection insulators for motors are known such as those disclosed in co-assigned U.S. Pat. Nos. 3,219,857, 3,748,510, and 4,227,108. Another connection insulator for this purpose, but formed of heat-shrinkable material with the bore of the insulator containing a mastic-like adhesive material, is disclosed in U.S. Pat. No. 4,381,464.
It would, however, be advantageous and desirable to provide a connection insulator that would be even more effective in providing and maintaining high insulation values for the electrical connections insulated thereby both during fabrication and during operation of motors which incorporate such connection insulators in the stator assemblies thereof. Further, it is believed that further improvements can be made in stator assemblies utilizing such connector insulators and in methods for making such assemblies.